Role of Organelle-localized Lys63-Linked Ubiquitination in Plant Immunity

细胞器定位的 Lys63 泛素化在植物免疫中的作用

• 批准号: 1645659
• 负责人: Lirong Zeng
• 金额: $ 68.5万
• 依托单位: University of Nebraska-Lincoln
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-05-01 至 2023-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1645659&HistoricalAwards=false
• 关键词: Role; Organelle; localized; Lys63; Linked

Crop yield losses caused by plant diseases are in the value of billions of dollars worldwide each year, which has made it an alarming threat to the food security in feeding a burgeoning global population. Understanding and eventually manipulating for crop improvement the key molecular mechanisms which plants use to defend against various pathogens is thus of considerable agricultural, economic, and social importance. Among the mechanisms pivotal for host defense is ubiquitination, a major post-translational protein modification process that occurs in plant, animal, and human cells. A particular type of unconventional modification of proteins by ubiquitin (lysine-63-linked ubiquitination, is well documented to be crucial in modulating human and animal innate and adaptive immunity. However, the roles of this type of ubiquitination in plant immunity and other plant physiological processes have been significantly understudied, even though this type of ubiquitnation is the second most abundant type of ubiquitination in plants. This project investigates the mechanistic basis of regulating plant innate immunity by this type of unconventional ubiquitination and includes education development for high school science teachers and minority undergraduate students and outreach to the Nebraska farmers and stakeholders.Initial work of this project has identified and preliminarily implicated two tomato RING type ubiquitin ligases, Fti1 and Fti1B and their closest homolog in Arabidopsis, AtFti1 and AtFti1B, respectively in FLS2-mediated plant pattern-triggered immunity (PTI). Fti1 and Fti1B and their Arabidopsis closest homolog were found to interact and work with UBC13 type ubiquitin-conjugating enzyme to catalyze K63-linked ubiquitination and Fti1B and AtFti1B were shown to be functionally conserved in FLS2-mediated PTI. Additionally, an isoform of AtFti1B was found to change subcellular localization to a yet undetermined organelle after PTI was induced by flg22 in the cell. In this project the investigators will elucidate the molecular mechanism underlying the regulation of plant PTI by AtFti1B/Fti1B-mediated K63-linked ubiquitination, with aims to (1) determine the role of AtFti1B isoforms in PTI and the molecular outcome of AtFti1B-BAK1/FLS2 interaction; (2) elucidate the biological significance of AtFti1B-BAK1/FLS2 interaction, the E3 ligase activity of AtFti1B, and the AtFti1B subcellular localization in plant immunity; and (3) identify novel components that are involved in the regulation of plant immunity by AtFti1B-mediated Lys63 ubiquitination. Fulfillment of this project will help integrally address two important, yet elusive questions in plant immunity: what are the roles and mechanisms of Lys63-linked ubiquitination and cell organelles in plant immune signaling. Considering the limited knowledge of Lys63-linked ubiquitination in plant biology in general, findings from this project will also assist our efforts to understand Lys63-linked ubiquitination in other plant physiological processes. Integral to this project will be extensive education and outreach activities to train high school science teachers and minority undergraduate students that are underrepresented in science through a High School and Undergraduate Science Connect Promoting Keen Interests in Research (HUSKER) program and to educate Nebraska farmers and stakeholders about the importance of basic research in crop improvement.

植物病害每年在全球范围内造成的作物产量损失价值数十亿美元，这对养活迅速增长的全球人口的粮食安全构成了令人担忧的威胁。因此，理解并最终操纵植物用于防御各种病原体的关键分子机制以用于作物改良具有相当大的农业、经济和社会重要性。在宿主防御的关键机制之一是泛素化，这是一种发生在植物，动物和人类细胞中的主要翻译后蛋白质修饰过程。泛素（赖氨酸-63-连接的泛素化）对蛋白质的一种特殊类型的非常规修饰在调节人类和动物的先天性和适应性免疫中是至关重要的。然而，这种类型的泛素化在植物免疫和其他植物生理过程中的作用已经显着研究不足，即使这种类型的泛素化是植物中第二丰富的泛素化类型。本项目旨在研究通过这种非常规泛素化调节植物先天免疫的机制基础，包括对高中科学教师和少数民族大学生的教育开发，以及对内布拉斯加州农民和利益相关者的宣传。本项目的初步工作已经鉴定并初步暗示了两种番茄RING型泛素连接酶Fti 1和Fti 1B及其在拟南芥中最接近的同源物，AtFti 1和AtFti 1B，分别在FLS 2介导的植物模式触发免疫（PTI）。Fti 1和Fti 1B及其拟南芥同源物与UBC 13型泛素结合酶相互作用，催化K63连接的泛素化，Fti 1B和AtFti 1B在FLS 2介导的PTI中功能保守。 此外，发现AtFti 1B的同种型在细胞中由flg 22诱导PTI后改变亚细胞定位到尚未确定的细胞器。本研究旨在阐明AtFti 1B/Fti 1B介导的K63-linked ubiquitination调控植物PTI的分子机制，目的是（1）确定AtFti 1B异构体在PTI中的作用以及AtFti 1B-BAK 1/FLS 2相互作用的分子结果;（2）阐明AtFti 1B与BAK 1/FLS 2相互作用的生物学意义、AtFti 1B的E3连接酶活性以及AtFti 1B在植物免疫中的亚细胞定位;和（3）鉴定通过AtFti 1B介导的Lys 63泛素化参与植物免疫调节的新组分。该项目的完成将有助于完整解决植物免疫中两个重要而又难以捉摸的问题：Lys 63连接的泛素化和细胞器在植物免疫信号传导中的作用和机制。考虑到Lys 63-linked ubiquitination在植物生物学中的知识有限，本项目的研究结果也将有助于我们了解Lys 63-linked ubiquitination在其他植物生理过程中的作用。该项目的组成部分将是广泛的教育和推广活动，以培训高中科学教师和少数民族本科生，这些学生通过高中和本科生科学连接促进对研究的浓厚兴趣（HUSKER）计划在科学方面代表性不足，并教育内布拉斯加州农民和利益相关者关于作物改良基础研究的重要性。

项目成果

MAC3A and MAC3B, Two Core Subunits of the MOS4-Associated Complex, Positively Influence miRNA Biogenesis

• DOI: 10.1105/tpc.17.00953
• 发表时间: 2018-02-01
• 期刊: PLANT CELL
• 影响因子: 11.6
• 作者: Li, Shengjun;Liu, Kan;Yu, Bin
• 通讯作者: Yu, Bin

Two Ubiquitin-Activating Systems Occur in Plants with One Playing a Major Role in Plant Immunity

• DOI: 10.1101/2021.09.02.458739
• 发表时间: 2021-09
• 期刊: bioRxiv
• 作者: Bangjun Zhou;Chaofeng Wang;Xuanyang Chen;Yi Zhang;Lirong Zeng